Modifying Hornady Custom Grade Sizing Die

[Old Navy]

The Redding Competition Shell Holders work pretty good. You can set some cam over on the press with the .010 one, then switch to the lower number ones till you find the one that gives you the bump you want.

Right on. The Redding dies are + sizes to keep from over bumping the shoulder down. Screwing the die down to get a little cam over is to insure the shell holder stays in contact with the die while giving you the bump you want. Presses, dies and shell holders are not the the same for everyone. I have a Redding +.004 in my press for several of my dies to keep from over bumping.

 

[rayporter]

i grind notches on my shell holders so i can tell them apart. one that has several thou ground off is easy to tell.

if you take too much off the shell holder the rim of the shell holder will pull off.

 

[divingin]

Relatedly....I've been told bump bolt gun shoulders 1 - 2 thou. And semi guns (this is a semi gun) 2-3 thou, due to looser tolerances needed for semi auto function. Dunno if true, but that's what I'm told.

About right for bolt guns, I'd say a bit shy for semi-auto. I look for 1-2 thou for bolt and 3-5 for semi (though I rarely shoot those anymore.)

With a bolt gun, though, I try not to bump from wherever they end up after the first firing; instead I wait until there is a need to actually push the shoulder back (i.e. you get a bit of drag closing the bolt.) That way you are actually working off the max case length for your chamber and bumping from there. If you just blindly push the shoulder back, you could very possibly (probably?) be pushing the shoulder back before you get to your chamber limits, which causes its own set of problems (case stretch and separation being the most notable.)

 

[GetReal]

About right for bolt guns, I'd say a bit shy for semi-auto. I look for 1-2 thou for bolt and 3-5 for semi (though I rarely shoot those anymore.)

With a bolt gun, though, I try not to bump from wherever they end up after the first firing; instead I wait until there is a need to actually push the shoulder back (i.e. you get a bit of drag closing the bolt.) That way you are actually working off the max case length for your chamber and bumping from there. If you just blindly push the shoulder back, you could very possibly (probably?) be pushing the shoulder back before you get to your chamber limits, which causes its own set of problems (case stretch and separation being the most notable.)

Yeah I'm giving a 6 ARC a try for "precision" shooting. Early reports are encouraging...even with Horn factory Black 105s / Match 108s.

Unlike my bolt guns that were + / - 0.0005 variation in the shoulder after 1st firing, this Bartlein bbld 6 ARC was + / - 0.001... from 1.209 to 1.207. So I bumped it back to 1.205. Its Hornady brass so I'm only figgerring to get 4 firings per case anyway. I'm told primer pockets go, first. Didn't anneal after this first firing. Will after the 2nd.

We'll see....